SOI硅微剂量计物理结构设计中的电荷收集及能量沉积特性模拟研究  

Simulation of charge collection and energy deposition characteristics in physical structure design of SOI-Si microdosimeter

作　　者：闫学文 靳海晶 李华 李德源[1,2] 乔霈 牛蒙青 YAN Xuewen;JIN Haijing;LI Hua;LI Deyuan;QIAO Pei;NIU Mengqing(China Institute for Radiation Protection,Taiyuan 030006;Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection,Taiyuan 030006)

机构地区：[1]中国辐射防护研究院,太原030006 [2]核药研发转化与精准防护山西省重点实验室,太原030006

出　　处：《辐射防护》2023年第5期443-450,共8页Radiation Protection

基　　金：山西省应用基础研究计划(20210302124486)。

摘　　要：采用TCAD软件和蒙特卡罗方法对SOI硅微剂量计的电荷收集特性与能量沉积特性进行了研究。分析了电场分布随探测单元形状、尺寸、电极注入深度、入射粒子种类和能量的变化情况以及微剂量谱随探测单元形状以及聚甲基丙烯酸甲酯(PMMA)转换层厚度的变化情况。模拟结果表明,在10μm的范围内,硅探测单元采用圆柱型或立方体结构对电荷收集效率和能量沉积的影响均很小,探测单元高度越高、半径越小,电荷收集效率越高,PMMA转换层的厚度对微剂量谱有一定的影响,随着PMMA厚度增加,中子和γ射线与PMMA作用产生的次级粒子被阻止在硅灵敏区内的份额增加,导致了微剂量谱峰值的增高。The charge collection characteristics and energy deposition characteristics of SOI-Si microdosimeter were studied by using TCAD and Monte Carlo method.The variation of electric field distribution with the shape and size of detection unit,electrode injection depth,incident particle type and energy was analyzed.And the variation of the micro dose spectrum with the shape and size of the detection unit and the thickness of the PMMA conversion layer was also analyzed.The simulation results showed that in the range of 10μm,the cylindrical or cubic structure of the silicon detection unit had little influence on the charge collection efficiency and energy deposition.The higher the detection unit height and the smaller the radius,the higher the charge collection efficiency.The thickness of PMMA conversion layer had a certain influence on the microdose spectrum.With the increase of PMMA thickness,the proportion of secondary particles generated by neutron andγ-ray that were stopped in the silicon sensitive region will increase,which leads to the increase of the peak value of the microdose spectrum.

关 键 词：SOI硅微剂量计 电荷收集 能量沉积 微剂量谱 

分 类 号：TL8[核科学技术—核技术及应用]